Effects of Reporter Gene on Mitochondrial Morphology and Function of i-CMs

Abstract

Background: Triple fusion (TF) reporter gene is ideal to track transplanted stem cell fate and function in treatment of myocardial infarction (MI) with stem cell transplantation, but its effects on on mitochondrial morphology and function of induced pluripotent stem cells (iPSCs)-derived cardiomyocytes (i-CMs) are still poorly understood. This study aimed to investigate the effects of the TF reporter gene on viability, proliferation, and differentiation ability, and the mitochondrial morphology and function of i-CMs. Methods: iPSCs were divided into two groups: iPSCs group and TF-iPSCs group (iPSCs transduced with the TF reporter gene). Moreover, iPSCs and TF-iPSCs were differentiated into i-CMs and TF-CMs respectively. γ-counter, micro-positron emission tomography (PET), bioluminescence imaging (BLI) and immunofluorescence were used to test the expression of the TF reporter gene in vitro. PET and BLI were used to verify the expression of the TF reporter gene in a rat myocardial infarction (MI) model 7 days after cardiomyocyte transplantation. Trypan Blue, CyQUANT cell proliferation and immunofluorescence assays were used to determine the effect of the TF reporter gene on the proliferation and differentiation of iPSCs. In vivo fluorescence and transmission electron microscopy (TEM) were performed to test the effects of the TF reporter gene on the mitochondrial morphology and function of i-CMs. Results: The TF reporter gene was stably expressed in vivo and in vitro. Compared with the iPSCs group, there were no significant differences in cell viability, proliferation, differentiation ability, and mitochondrial morphology and function from the TF-iPSCs group. Conclusions: This study demonstrated the safety of the TF reporter gene in multimodality imaging of transplanted cells at the mitochondrial level.